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Is it possible to run a laptop off the battery while the AC is plugged in? I can play games no problem while just the battery is plugged in, but obviously that means I have to let it charge after every hour or so. But, when I plug it in to charge, it can't handle any video games anymore.

I thought it was the brick in the power cord going out, but I just bought a new one and it still doesn't work. The specs are actually better than the old cord. I think the problem is an over heating problem in the AC outlet, but if it charges the battery while I play, it would work just fine running solely off the battery.

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You kind of forgot to describe the problem. You say "it can't handle any video games anymore". Well, what happens when you try? –  David Schwartz Oct 15 '12 at 16:55
    
well, I get a black screen basically but the computer is still on, everything else is still usable, like push to talks for ventrilo or if I'm in skype the call continues and I can still hear the game sounds, just cant see anything on the screen, I cant pull up any thing... the screen just goes black and wont come back on –  Deric Hatchett Oct 15 '12 at 17:16
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4 Answers

You may not have a problem with the charger at all, but a problem with heat or power distribution elsewhere.

When you unplug from a charger, current OSes do a number of things. They turn down the CPU, lower screen brightness, often schedule hard drives to spin down, etc.

What I'd suggest is that you turn down the settings so that you use the same power settings whether you are plugged in or on battery. In Windows 7, these are managed in Control Panel\System and Security\Power Options\Edit Plan Settings, then click Change advanced power settings. There you should see a lot of settings. At a minimum, you should turn cooling up (to Active) and turn your CPU down.

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well this laptop is 3 years old and this is a recent problem, I'm not playing different games, it cant handle the same ones it could before and why would it be able to handle with the battery on highest settings, but not plugged in? they have the same output/input min/max –  Deric Hatchett Oct 15 '12 at 16:56
    
Thank makes me think it's heat even more. Try blowing the fan out with compressed air, and make sure that any ventilation ports are clear. If they've gotten clogged with dust, it could explain a lot. Also, if your laptop has a removable battery, try removing it... Charging a battery generates a lot of heat, and it might help diagnose things. –  Alan Shutko Oct 15 '12 at 17:01
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I think @AlanShutko was suggesting that when plugged in, the power settings may be such that the CPU runs at the highest setting (meaning the hottest setting as well), and as your system has gotten older, the cooling may not work as well. Most CPUs will throttle themselves when they start to overheat. It could be that the CPU is already throttled due to the power settings when on battery, so you don't run into an over-heating issue then. –  ernie Oct 15 '12 at 17:03
    
I've tried pulling the battery out, and its actually on a cooling pad, I've thought the issue was a number of things before I concluded then, and the removable battery running on its own is the only way it runs games properly, otherwise after a few min I'll get a black screen... but sound still works and the computer is still on, so if I'm on skype in a call with someone, I can keep talking to them but I wont be able to use the laptop until I power it down but I'm afraid to take my laptop apart I know of people ruining their laptop by cleaning it –  Deric Hatchett Oct 15 '12 at 17:12
    
also, I run it on the highest settings while just the battery is plugged in, thats actually how I concluded it isnt the graphics card due to the issue I pointed out –  Deric Hatchett Oct 15 '12 at 17:13
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The answer to your question in bold is no, you cannot run on battery when the power cord is plugged in. There are "smart" power adapters that can avoid charging the battery when plugged in, but they will still supply power to the laptop.

Have you checked the CPU usage in Task Manager (use Ctrl+Shift+Esc to launch it)? If the power adapter is not good enough, there's a chance of the CPU usage going up quite high and making the system unusable when connected to mains (which is what seems to be happening with your games). The new one you bought, although with better specs, may not be good enough either.

Search on the web for something like "high cpu usage power adapter" and you'll find that this is a common issue across many laptop makes and models. The best solution is to get a good power adapter, preferably from the laptop manufacturer.

Update: It could also be a problem with the battery, since the laptop is more than three years old. See Why does the CPU usage reach 100% when laptop is plugged in?

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well this laptop is 3 years old and this is a recent problem, I'm not playing different games, it cant handle the same ones it could before and why would it be able to handle with the battery on highest settings, but not plugged in? they have the same output/input min/max –  Deric Hatchett Oct 15 '12 at 17:03
    
Since it's three years old, it could also mean a failing battery. I updated the answer accordingly with another link. –  M K Oct 16 '12 at 6:49
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The answer to your question in bold: Yes, it is possible to run a laptop of battery while AC is plugged in. But I only found this option on a single model of laptop (Dell Lattitude D series) which makes me think it is quite rare.

Note that even if it works on your laptop it will be a workaround, and the real problem should be found and fixed. For an old laptop the obvious candidate includes heat problems.

(This despite reading your problem description: My experience with old broken laptops is almost always due to heat. Alternative problems are blown capacitors, but that makes less sense in your problem description).

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Please specify the make and model of your laptop, with special care describing the GPU(s) in it. I suspect that this is something to do with switchable graphics and drivers not appropriate for the situation.

Also, If you use Win7, I'd check the Power settings, I think there is an Advanced tab somewhere where you can specify all kinds of advanced stuff, like which GPU is used under what power conditions, etc.

Also, if you unplug the power cord, does the image come back again?

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